Text B. Conditioned Reflexes

All the visceral and somatic reflexes including the protective, feeding and others are formed by various internal and external stimuli. These stimuli produce reactions not depending on surrounding conditions. The great Russian physiologist Pavlov called them nnconditioned reflexes.

In human beings the nervous system has the additional ability to form cortical associations which increase the range of reactions. This function is obtained by all the human beings and formed upon signalization, i.e. the process in which an ineffective reflex stimulus forms the same reactions as the stimulus with which it has become associated. Pavlov called these individually obtained reflexes conditioned, because they are developed only in connection with some other reflexes.

It is through constant contacts of life that men develop many conditioned reflexes. They begin to develop already in infancy. During human development their number is much increased through training and education.

In experimental conditions it was determined by Pavlov that many new conditioned reflexes to stimuli not supplied by Nature could be established in dogs. But such stimuli had to be associated with those which formed an unconditioned response. Pavlov determined that in higher animals it was in the cortex that conditioned reflexes were formed.

LESSON 22

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I. Запомните факты, изложенные ниже:

Do you know that

1. the vision centres are located in the occipital [ok'sipitl] area of the cortex? 2. the nervous system of the human being has about ten times more nervous cells than the number of all people in the world? 3. the stimuli pass into the brain through the spinal cord very rapidly — about 100 m per second?

II. * Закончите предложения, выбрав необходимые по смыслу слова:

1. The ear is the sense organ of (vision, hearing). 2. The human being smells with (the nose, the eye). 3. The motor cortex controlling many body movements (becomes tired rapidly, is almost never tired). 4. The stimuli from different parts of the human body come to the brain through (the blood vessels, the nerve fibers in the spinal cord).

III. На основании следующих формул напишите и назовите инфинитивы (см. таблицу 22, стр. 292)

1. от глагола to determine:

2.* От глаголов to add, to bring, to connect

IV. * Найдите и назовите инфинитивы:

1. Не may examine the patient. 2. He may be examining the patient now. 3. He may have examined the patient already. 4. He may be examined by Doctor Sedov. 5. He may have been examined by 11 a.m.

V. Прочтите следующие предложения, обратите внимание на перевод модальных глаголов и инфинитивов, стоящих после них. Ответьте на вопросы:

1. Не cannot do it.

Не cannot have done it. Can he have done it?

2. He may perform an operation on the heart. He may have performed an operation on the heart.

3. You must deliver a lecture. You must have delivered a lecture.

Он не может это сделать. Не может быть, чтобы он это сделал. Неужели он сделал это? Он может быть (возможно) делает опе­рацию на сердце.

Он может быть (возможно) сделал операцию на сердце. Вы должны читать лекцию. Вы должно быть (вероятно) прочита­ли лекцию.

1. К какому времени относится действие, выраженное перфектным инфинитивом? 2. В каких предложениях обычно употребляется модальный глагол сап с Perfect Infinitive, и как они переводятся? 3. Как переводятся модальные глаголы may и must с Perfect Infinitive?

VI. Переведите следующие предложения:

1. Can the patient have developed such a bad pain in the stomach after taking the medicine? 2. The infant is quiet now. Mother must have fed it. 3. The blood pressure may have decreased after the administration of this drug. 4. Can the investigator have drawn such a conclusion after a number of experiments?

VII. Выучите следующие слова и словосочетания: delicate ['delikit] а тонкий; слабый (о здоровье); хрупкий inhibit [in'hibit] v подавлять; тормозить; сдерживать allow [a'lau] v позволять, разрешать

provide [pra'vaid] v обеспечивать, снабжать (with); предусматривать (for); provided cj при условии (что); если только; в том случае, если smooth [smu:d] а гладкий; ровный; спокойный purpose ['p3:pas] п цель

fall [fo:l] (fell, fallen [fo:ln]) v падать, спадать; понижаться); to fall asleep заснуть; to fall ill with заболеть

significance [sig'nifikans] n значение, важность

quiet ['kwaiat] а спокойный, тихий; to become quiet успокоиться

drop [drop] и ронять; капать; закапывать (into); падать; и падение; капля

though [dou] adv хотя, тем не менее

spread [spred] (spread, spread) v распространять(ся)

VIII. Переведите однокоренные слова и найдите в них суффиксы и префиксы:

act, action, activity, react, reaction, reactive; significance, significant, insignificance, insignificant, insignificantly; to tire, tired, tiredness; inhibit, inhibition, inhibitory, inhibitor; quiet, quietly, quietness

IX. Выучите следующие словосочетания, обращая внимание на предлоги:

to provide with, to provide for, to fall ill with, to drop into, for some purpose, to be of some significance, to react to smth, to spread over / to smth.

X. Переведите следующие словосочетания:

а) слабое здоровье, хрупкие клетки, тонкая операция; гладкие мышцы, ровная боковая поверхность; тихий отдых, спокойный сон; крепкое здоровье, глубокий сон

б) падать; я упал; больной заснул; я уронил термометр; закапать лекарство в глаза; он заболел пневмонией; позволить больному ходить; больному позволили сесть; врач не разрешает мне утомляться; обеспечить;

наша библиотека обеспечивает нас книгами; это было предусмотрено заранее (beforehand); мы провели много экспериментов для этой цели; сон имеет большое значение для жизнедеятельности человека; боль распространилась по руке

XI. * Переведите слова, данные в скобках, а затем переведите предложения:

1. When the man feels (усталость) he (засыпает). 2. The external surface of the liver is (гладкая). 3. Sleep is of a great protective (значение) to the human being. 4. Please be (тихо), the patient has just fallen asleep. 5. When the doctor was examining the patient he determined that the heartbeat was (замедленный).

XII. 1. Прочтите текст С. 2. Озаглавьте его. 3. Найдите предложения с подлежащим, выраженным словом 'one'. 4. Переведите эти предложения. 5. Выпишите английские эквиваленты следующих словосочетаний:

1. для этой цели; 2. полный покой; 3. распространяется по коре головного мозга; 4. имеет большое защитное значение для; 5. глубокий спокойный сон; 6. жизнедеятельность

Text С

The nervous cells of the cortex are the most delicate of all the cells of the human body.

It is at the moment of tiredness of the cortical nervous cells that the process of inhibition begins to act. This process does not allow new stimuli to pass to the tired areas of the brain. To provide the smooth work of the brain the nervous cells must be well supplied with oxygen and feeding substances. And for this purpose any human being must have regular complete rest, i.e. sleep.

When the process of inhibition extends over a great number of cells, spreads widely over the cortex and even over the subcortical areas of the brain one falls asleep.

When one sleeps the vital activity of the nervous system is restored. So sleep is of a great protective significance to the human being.

The man sleeps about one third of his life. Numerous investigations and experiments have shown that sleep is more necessary for the human being than food. One can live longer without food than without sleep.

During a sound quiet sleep the whole activity of the human organism changes, the body metabolism decreases, the respiratory and pulse rates become slower, the body temperature drops. Though the stimuli continue to come into the brain, the inhibited cortical cells do not react to them. 124

XIII. Choose the appropriate answer:

1. Why had the patient's condition been complicated? (a) The patient's condition has been complicated today because he feels pain in the heart area, b) The patient's condition had been complicated because he did not receive any treatment last month, c) The patient's condition will have been complicated if he does not receive any treatment by tomorrow.) 2. What has been controlled? (a) The disease will have been controlled by the beginning of the next week, b) The disease had been controlled before the patient was discharged from the hospital, c) The disease has already been controlled and the patient is able to start his work again.)

XIV. Read the pairs of sentences and answer the questions:

1. Patient Ivanov has already been operated on. Patient Smirnov must be operated on. Кого из них прооперировали?

2. The new book on the physiology respiration will have been published by the end of the year. The book "The Anatomy of the Cardiac Blood Vessels" by Prof. Seraphima Samoilova has already been published in Leningrad. Какая из книг будет издана?

XV. Translate the pairs of sentences. Define the infinitives:

1. The patient may be discharged soon. The patient may have been discharged by the 15th of the last month. 2. The process of inhibition in the cortex of experimental animals must be described in detail. The process of inhibition in the cortex of experimental animals must have been described after the observations.

XVI. Recall the usage of the word 'one'. Translate the following sentences:

1. The brain is one of the most complicated, mechanisms that has ever been constructed by nature. 2. In patients with tuberculosis the morning temperature is usually normal but the evening one is high. 3. In pneumonia one may observe considerable changes in the white blood cell count. 4. It is in infancy that one begins to develop first conditioned reflexes. 5. The right lung has three lobes and the left one only two.

XVII. Put the verbs given in brackets in the appropriate tense. Translate the sentences:

1. Important findings (to obtain) by the investigator before he finished his observations. 2. All the observations (to analyse) and (to summarize) by the physiologist by the end of his experimental work next month. 3. The patient (not to feed) since early morning because he will be operated on today.

XVIII. Supply participles instead of subordinate clauses:

1. The pleura is a special tissue which covers the lungs with a thin layer. 2. Different actions which are repeated every day before going to bed also act as stimuli which produce the process of inhibition.

XIX. Read Text D. Say about the influence of sleeplessness the human organism:

TextD

One of the scientific research institutes in Chechoslovakia carried out an interesting experiment. Six young persons—four men and two girls did not sleep for 124 hours. They were under the constant observation of the doctors who took their cardiograms, determined the pulse and blood pressure and carried out many other investigations.

Not to fall asleep they were allowed to do physical exercises, dance and play, but they were not allowed to take any stimulants. Vision, hearing and various reflexes were often examined during the experiment.

The experiment was successful. Its findings showed that prolonged sleeplessness increased the amount of sugar in the blood, decreased the level (amount) of vitamins B, and B₆, produced considerable increase of white blood cells and decreased the amount of iron in the blood.

LESSON 23

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